Syringe assembly



May 19, 1959 c. o. KENDALL 2,887,108

SYRINGE ASSEMBLY Filed Nov. 18, 1955 i i' ff 24 if i. ze

IN V EN TOR.

United States Patent O SYRINGE ASSEMBLY Charles 0. Kendall, Waldwick, NJ., assignor to Becton,

Dickinson and Company, Rutherford, NJ., a corporation of New Jersey `Application November 18, 1953, Serial No. 392,790 1o claims. (cl. 12s-21s) This invention relates to a structurally and functionally improved hypodermic syringe assembly and also teaches a novel method of transferring medicament to that assembly from the vial.

As is well appreciated, the accepted technique of charging a syringe assembly with a desired volume of medicament involves the sterilizing of that assembly and the use of a container commonly termed a vial which is lled with liquid medicament in a volume equal to where the indicia ordinarily `associated with the barrel indicates that the existing Vspace between the plunger and syringe end defines the desired capacity. With such retraction or aspirating of the plunger, ordinary room air is drawn through the lumen of the needle and into contact withits sterilized surfaces, as well as the similar surfaces of the plunger and barrel bore.

The point of the needle is now caused to pierce the seal which forms a part of the vial assembly and the latter is ordinarily supported in` an inverted position.

Accordingly, the needle point will now be immersed within the liquid medicament. Thereupon, the plunger is advanced. This discharges the air contained within the syringe through the needle bore into the interior of the vial.

the liquid from the vial will be drawn through the needle bore into the syringe barrel.` The movement of the plunger will be continued until it registers with the indicia mark on the barrel which corresponds to the de,- sired dosage to be injected.

As will be obvious under this procedure, the sterile surfaces of the syringe assembly are exposed to the air within a given room, which air may be laden with bac- Accordingly,` the pressure within the` latter` is increased. T herefore,` as the plunger is now retracted,`

teria to a pronounced degree. Therefore, in a subse-` quent injection, such bacteria will be discharged with the medicament into the patient. Additionally,` each time liquid medicament is withdrawn from the vial, the` latter will receive an additional volume of room air. Ordinarily, a vial may contain ten cc. of liquid medicament. Thisrmay be withdrawn in the form of ten successive one cc. dosages under the aforedescribed technique. It is apparent that with the withdrawal of the initial dosage, contaminated air is discharged into the vial interior. The density of contamination will increase with each withdrawal of medicament; it being obvious that a high level of contamination will exist during the withdrawal of the final dosages of medicament from the vial. c

By means of `the present teachings, the sterility of the interior surfaces of the syringe assembly are maintained. Also, the medicament Within the vial is not contaminated by the introduction of non-sterile air at the time the syringe is charged or lled with medicament.

While in certain aspects it is a primary object to furnish a syringe assembly which may have a one-time use, certain aspects of this invention are of Value, not alone where a syringe is discarded after beingemployed for one hypodermic injection, but also in connection with an assembly which will be used to achieve a number of injections.

A still further object is that of providing a syringe assembly in which the needle is permanently secured against detachment from the barrel Iby means Iof an improved construction, and in which such mounting may be achieved with minimum eifort.

Among other objects of the invention are those of designing an assembly which will include relatively few parts, each individually simple and rugged in construcJ tion, such parts beingcapable of ready manufacture and association with each other to furnish a sterile unit which;

will remain free from contamination for indefinite periods of time; that unit being capable of being readily potentializedby the physician or other user `so that a proper injection may be quickly made.

j With these and other objects in mind, reference is had to the attached sheet of drawings illustrating practical embodiments of the invention and in which:

Fig. l shows the assembly in its initial condition;

Fig. 2 is a plan view thereof;

Fig. 3 is a perspective View of one form of piston"` which may be embodiedin the assembly;

Fig. 4 is a similar view of an alternative form of piston;

Fig. 5 shows the syringe assembly in process of being filled or charged with medicament; and

Fig. 6 illustrates the syringe ready for use.

In Figure l, a syringe assembly has been illustrated in its initial condition.

its sursyringe barrel, which preferably may be `formed of glass or any other suitable material and preferably `has a reduced forward or outer end portion 11, dened by a ange 12. This end of the syringe barrel is closed by a headed stopper 13 of pierceable material such as Irubber and which may have its inner face recessed. The

outer barrel surface presents the usual indicia indicative of syringe volume. The stopper is prevented from being displaced preferably by employing a retaining ring The surface of the stopper 14, conveniently `of metal. head is preferably protected by a seal 15 which may be formed of aluminum or other material and conveniently provided with a tab 16 such that the user may readily strip it off the assembly.

Adjacent its opposite end, barrel 10 is conveniently provided with an outstanding ilange 17. At this zone, its bore supports a piston 18 again preferably formed of rubber. In order that the latter may be manipulated,

a coupling structure is furnished. As shown, this con-` veniently includes a threaded recess 19 in the outer face of the piston. An actuator for the piston has been shown at 20 and as illustrated is furnished with a thumb portion or flange 21 at its` outer end. At its opposite` end, it is` provided with a screw-threaded extension `2a uPatented Maty 19, 1959` This is the condition in which it is received by the physician or other technician. All

Its opposite ends are sealed against the entrance which may be received within the recess 19 in order to furnish the second portion of the coupling. Obviously, other forms of coupling than that illustrated may be employed. suitable plastic.

With the stopper 13 closing one end of the barrel bore and piston 18 closing the opposite end of the same, it is apparent that the interior of that bore will be sealed. A needle 23 having a length such that it may be accommodated between these end seals is disposed within the bore and has its inner end mounted by a hub 24. The latter includes a cup-shaped base 2S with which a detent structure is associated. Preferably the detent takes the form of a suitable number of outwardly extending resilient tongue portions 26 which are integral with the side walls of the cup 25. That cup has a diameter such that it may be snugly accommodated within the reduced bore of the barrel dened by portion 11. However, the outer ends of the tongues will extend beyond such a diameter. A receiving and retaining part is provided by the lower edge or wall portion defining an annular groove or recess 27 in the reduced part 11 of the barrel.

Communication is initially established between the interior of the barrel and the bore of `needle 23 by furnishing a passage between the base of the latter and such barrel interior. This passage may be formed in one of a number of different manners. Preferably, as shown, it is included within the extension 27 of piston 18 as shown in Figs. 3 and 4. In the first of these figures, the extension is preferably integral with the body of piston 18. The extension has a diameter such that it may fit into the space defined by cup 25. Grooves 28 extend axially of the extension and are continued in the form of grooves 29 across its outer face. In Fig. 4, the extension has been indicated by the reference numeral 30. Again it may be integral with piston 18. A suitable` number of ribs 31 have been illustrated as extending axially of and transversely across the surface of this extension.

In any event, it will be appreciated that with the selected extension disposed within the cup 25 of the needle hub, a passage exists from the bore of needle 23 past the extension and so to the interior of barrel at a point beyond piston 18. Therefore, when the latter is projected and the pointed end of the needle has pierced and emerged from closure 13, continuing movement of the piston toward the reduced end portion 11 of the barrel will cause the air which would otherwise be entrapped within the barrel, to be expelled through the bore of the needle.

The detent assembly comprising one or more tongues 26 and the receiving recess or groove 27 therefor, according to the preferred embodiment of the invention, functions as a lock. In other words, when its parts are once engaged, no subsequent release of these elements will occur. Aside from the fact that functionally equivalent structures might be furnished in lieu of the tongue or tongues, it is also apparent that couplings other than that shown might be employed between the actuator and piston. Regardless of this, however, as the piston is projected to a point where it is immediately adjacent the outer end portion of the barrel, the parts of the detent will either automatically couple or else may be manipulated to elect such coupling.

against the lower edge or wall of groove. 27. Thel If desired, the actuator 20 is formed of a stopper being under slight compression, it will yieldingly and rmly urge these tongues to maintain the locked position of the parts; it being apparent that as the parts have been projected, the edges of the tongues have overridden the lower wall defining groove 27 or any equivalent recess. Thus, the needle is firmly supported against movement with respect to the barrel. Upon the piston being retracted, it will separate from the parts of the i needle grouping, which will remain properly supported in projected position.

The assembly will as afore stated preferably come to the physician or other user in the condition illustrated in Fig. 1. The parts will have been sterilized and the air within barrel 10 will be free from all bacteria or other contamination. If now it is desired to inject by means of the `syringe, the physician will couple an actuator 20 with piston 18 and will project the latter so that the point of needle 23 pierces stopper 13 and extends beyond the end of the same. Of course, prior to this operation, he will have removed the seal 15 which has maintained the outer stopper surface in sterile condition, or in the absence `of such a seal, will have wiped the surface of stopper 13 with lan antiseptic solution. A vial 32 is employed, its seal (not shown) removed, and the projecting end portion of needle 23 caused to pierce the vial stopper 33. Thereupon, projection of piston 18 continues.

As afore brought out, with the projection of that piston the air within the barrel is vented through the bore of the needle. The point of the latter extending into the body of liquid within the vial, the air is therefore discharged into the interior of that vial. However, such air will be free from contamination. Therefore, the solution within the vial will not be subjected to deteriorating or dangerous factors as has heretofore occurred, where non-sterile air is discharged into the vial prior to drawing a desired amount of medicament from the latter.

In the present instance, a volume of sterile air corresponding to the medicament dosage to be injected replaces the liquid which is withdrawn from the vial. Of course, if only a partial filling of the syringe barrel is contemplated, then the user will not introduce the point of the needle through stopper 33 as soon as that point emerges from stopper 13. Rather, piston 18 will be projected to a point Within the barrel corresponding to the volume of medicament to be injected and then only will the needle be thrust through stopper 33. Thereupon, by fully projecting and then retracting piston 18, the proper volume of air is discharged and the desired amount of liquid is drawn into the barrel as in Fig. 6. Needle 23 is now withdrawn from the vial and the assembly is ready for use.

As will be appreciated, the needle will be firmly supported when its assembly is in the position shown in Figs. 5 and 6. After the injection of a patient has been completed and the needle withdrawn, the apparatus-may be discarded in toto. An effective seal is furnished, as a consequence of the present structure, between the stopper recess surface and the face of hub 24, such that no leakage of medicament will occur between these parts.

Obviously numerous changes in construction may be resorted to and the steps of the method may be modified within the coverage of the appended claims:

I claim:

1. In a syringe assembly in combination, a single barrel `having forward and rear ends ard formed with a bore, a hypodermic needle pointed solely at one end and blunt at the other, said needle being disposed within said bore with its points extending adjacent the forward end of the same, a piston also disposed within said bore to the rear of said needle and bearing against the adjacent blunt end of the latter, the space between said piston and the forward end of the barrel defining a medicament chamber, said piston being movable towards the forward end of the barrel to thrust against the adjacent blunt end of said needle and project the point of the latter beyond such barrel end, means adjacent the blunt needle end providing a passage for the expulsion of air from the barrel interior through the needle lumen dur'mg such projection, means for retaining said needle against subsequent retraction and means for retracting said piston to draw medicament from the pointed projected end of the needle through the lumen thereof and fill the barrel chamber with such medicament between its forward end and said piston.

2. In a syringe assembly as specified in claim l, the aggregate length of the piston and needle being substantially equal to the length of the bore within which they are disposed and whereby said piston is initially disposed adjacent the rear end of said barrel.

3. In a syringe assembly `as specified in claim 1, and said passage including relatively raised and recessed surfaces forming a part of said piston, such that air will be vented therethrough and through the lumen of the needle as said piston is moved towards the forward barrel end.

4. In a syringe assembly as specied in claim 3, a hub secured to said needle adjacent its blunt and, such relatively raised surfaces engaging inner faces of said hub and the latter and said recessed surfaces providing said passage.

5. In a syringe assembly as specified in claim 1, said needle-retaining means comprising a hub secured to and extending rearwardly of the blunt end of the needle, relatively raised and recessed surfaces forming parts of the barrel bore adjacent its forward end and means extending outwardly from the hub to override and latch beyond certain of such surfaces.

6. In a syringe assembly as specified in claim 1, a reduced portion defining the forward end of said barrel and its bore, relatively raised and recessed surfaces in said bore within the zone of said reduced portion, a hub secured to the blunt end of the needle and rearwardly directed tongues extending radially of said hub to override and latch beyond certain of such surfaces to provide said retaining means.

7. In a syringe assembly as speciiied in claim 1, a stopper closing the forward end of said bore and being penetratable by the pointed end of said needle.

8. In a syringe assembly as specified in claim 7, and means engaging said barrel and stopper to prevent a dislodgement of the latter as the pointed needle end passes therethrough.

9. In a syringe assembly as specified in claim 1, a reduced barrel and bore portion adjacent `the forward end of said barrel, a seal positioned in that end of the bore and formed with a recess in its inner face, a hub secured to the blunt end of said needle, a forwardly extending part in said hub, the latter having a diameter such that it may be received in said reduced bore portion and said forwardly extending part being receivable in the recess of said seal.

10. In a hypodermic syringe assembly in combination a bored barrel having an outer end, a piston within said bore, an extension forming a part of said piston and projecting in the direction of said outer end, a hollow needle pointed at one end and blunt at the other, a hub secured to the latter end and in communication with the lumen thereof, said extension beingdisposed within said hub and parts assuring a spacing of the hub from said extension such that a passage is furnished from the needle lumen to the barrel bore.

References Cited in the le of this patent UNITED STATES PATENTS 1,767,304 Morton June 24, 1930 2,186,888 Tullar et al. Jan. 9, 1940 2,408,323 Lockhart Sept. 24, 1946 2,460,039 Scherer et al. Jan. 25, 1949 2,489,600 Tydings et al Nov. 29, 1949 2,568,173 Spivack Sept. 18, 1951 2,639,709 Volgenau May 26, 1953 2,679,247 Mendez May 25, 1954 2,696,212 Dunmire Dec. 7, 1954 2,704,072 Sarnoif Mar. 15, 1955 FOREIGN PATENTS 1,003,347 France Mar. 17, 1952 

